1. The Field of the Invention
This invention relates to a system for forming a composition of matter with an optimized filler in which a filler is mixed or blended with a material to form the composition, which filler has been optimized and more particularly to a system and method for forming a composition or composite using one or more selected fly ash materials as a filler with a plastic material which filler is selected and processed as necessary to attain desired processing properties and/or end product properties.
2. The Relevant Technology
A wide variety of manufactured products are made from materials of the type which may permit blending or mixing in a filler before formation of the product. Fillers are typically low cost materials that can range from glass beads to saw dust and are used to reduce the amount of the other material (e.g., plastic) which is typically a more expensive material. Fillers may be selected for reasons that include not only cost reduction but also control of the mechanical properties of the final product. Fillers are typically added as a solid material to a material that can be a liquid or a powder and is typically a liquid at room temperature or is a liquid at an elevated temperature forming a melt. The melt or powder is then processed in some way (e.g., cured, extruded, molded) and then cured or hardened.
Plastics or plastic resins are principally polymers that are synthetically made or, if naturally occurring, are modified in some way. Resin manufacturers convert raw materials like crude oil or natural gas into basic polymers that are used in the manufacture of various goods. Reportedly, thermoplastics are the largest class or category of polymers produced. Polymers are heated to become a liquid and are often modified by incorporating additives which also modify the physical properties of the polymer when cured and/or to reduce the cost of materials and, in turn, the cost of the final product in addition to fillers. M. Xanthos, Functional Fillers For Plastics (Wiley-VCH 2005) pp. 1-6.
FIG. 1 shows in simplified form a process for forming a polymer product with a filler. A selected resin 10 along with a chosen filler 12 are blended together 16 with optional additives 14. The resulting mix, melt or blend 16 is then supplied to a forming device/machine 18 to form a product.
Additives that can be combined with resins may include colorants, lubricants, coupling agents and stabilizers. The additives also can include foaming agents to control the density of the resulting material. For example, it is known that low cost fillers like clay, ground limestone, talc and other powdered or granulated materials can be added to or combined with a resin to reduce the cost of the material to produce a given product because less resin is being used. A. Brent Strong, PLASTICS Materials and Processing, (3rd Ed. Pearson Prentice Hall 2006), pp. 1-21. Other fillers like calcium carbonate, silicon, glass beads, sawdust, shavings as well as fibrous materials like flax and hemp may also be added to impact on the make up and mechanical capabilities of the final product.
What is or constitutes an additive or a filler for a polymer is not easily defined. Some additives have certain geometries (e.g., fibers, flakes, spheres, particulates). Particulates usually are spherical or deemed to be spherical; and they have a length to width ratio (i.e., aspect ratio) that is typically regarded as 1. They are not fibers, but instead are typically some form of mixture of different sizes and shapes of a material. The particles are often mixed into the liquid or molten plastic. Mixing a filler into a resin obviously thickens the mixture in much the same way a flour thickens dough. In some cases, fillers may be added to thicken a mixture to control viscosity. If viscosity is too low a thixotrope (e.g., fumed silica) may be added to thicken the molten mixture. If viscosity is too high because a certain amount of filler is needed to control, for example, flammability, a viscosity reducer (e.g., organic acid salts) can be used. A. Brent Strong, Fundamentals of COMPOSITES MANUFACTURING, Materials, Methods and Applications, (2nd Ed, Society of Mfg Engineering 2008) pp. 42-43, 70; M. Xanthos, Functional Fillers For Plastics (Wiley-VCH 2005) pp. 6-7.
A major contribution of a filler has been and still is the lowering cost of materials because expensive resin is replaced by less expensive filler. But it is now recognized with increasing clarity that a filler can be used to impact the physical structural characteristics of the resulting product. Glass beads, sawdust, and chips all can be added for different reasons to produce products with different mechanical properties.
Fillers are also known to have some impact on processing characteristics of a melt. For example, unfilled polymers behave like non-newtonian fluids with viscosity changing during melt processing. The addition of fillers will increase the viscosity of the liquid; and that increase in viscosity changes the flow and other processing characteristics of the liquid. However, packing of the filler and particle size distribution of the filler itself is not recognized as a factor influencing the rheology of a melt and have not heretofore been used to regulate or control the viscosity of the melt. Rather, such factors are believed to impact on the material characteristics of the resulting cured or hardened material. M. Xanthos, Functional Fillers For Plastics (Wiley-VCH 2005) pp. 32-35.
Widespread use of fillers over time has led to classification of different types of fillers along with fillers that have known benefits or functions. M. Xanthos, Functional Fillers For Plastics (Wiley-VCH 2005) pp. 12-15. While the function and use of many different kinds of fillers is known, the process of selecting a filler is largely empirical. Many different kinds have been used in a variety of different ways which is now so well recognized that the information about such fillers has become textbook material. Further, the quality of certain fillers is understood to vary with, among other factors, the source. Thus, many materials that would be suitable or even ideal fillers are not used because the quality is inconsistent not only from one source to another but also with in some batches. Such materials have thus not been used or selected notwithstanding their lower cost and availability.
There is a need for a system to identify or optimize a filler or combination of fillers selected in any composition of matter and more particularly for the selection and optimization of low cost fillers that can be processed or blended to make a uniform filler with consistent physical attributes particularly in resins such as plastics. There is also a need for fillers that will impact on the viscosity of the melt and allow for the reduction of production costs.